Results 31 to 40 of about 1,731 (272)

Robust Approximate Inverse Preconditioning for the Conjugate Gradient Method [PDF]

SIAM Journal on Scientific Computing, 2000
The authors present a stabilized approximate inverse algorithm for arbitrary symmetric positive definite matrices to be used in preconditioned conjugate gradient methods. They also investigate another approach to prevent breakdowns that is based on the technique of diagonally compensated reduction of positive off-diagonal entries. Numerical results for
Benzi, M., Cullum, J. K., Tůma, M.
openaire   +1 more source

Numerical Algorithms for Computing an Arbitrary Singular Value of a Tensor Sum

Axioms, 2021
We consider computing an arbitrary singular value of a tensor sum: T:=In⊗Im⊗A+In⊗B⊗Iℓ+C⊗Im⊗Iℓ∈Rℓmn×ℓmn, where A∈Rℓ×ℓ, B∈Rm×m, C∈Rn×n. We focus on the shift-and-invert Lanczos method, which solves a shift-and-invert eigenvalue problem of (TTT−σ˜2Iℓmn)−1 ...
Asuka Ohashi, Tomohiro Sogabe
doaj   +1 more source

On numerical solution of nonlinear parabolic multicomponent diffusion-reaction problems

Analele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2021
This work continues our previous analysis concerning the numerical solution of the multi-component mass transfer equations. The present test problems are two-dimensional, parabolic, non-linear, diffusion- reaction equations. An implicit finite difference
Juncu Gh., Popa C., Sarbu Gh.
doaj   +1 more source

Preconditioned Conjugate Gradient Methods for the Navier-Stokes Equations [PDF]

Journal of Computational Physics, 1994
A preconditioned Krylov subspace method (GMRES) is used to solve the linear system of equations of the unsteady two-dimensional compressible Navier-Stokes equations. The Navier-Stokes equations are discretized in an implicit, upwind finite-volume, flux-split formulation.
Ajmani, Kumud, Ng, Wing-Fai, Liou, Meng-Sing   +2 more
openaire   +1 more source

A new approximate inverse preconditioner based on the Vaidya’s maximum spanning tree for matrix equation AXB = C [PDF]

Iranian Journal of Numerical Analysis and Optimization, 2019
We propose a new preconditioned global conjugate gradient (PGL-CG) method for the solution of matrix equation AXB = C, where A and B are sparse Stieltjes matrices. The preconditioner is based on the support graph preconditioners.
K. Rezaei, F. Rahbarnia, F. Toutounian
doaj   +1 more source

Time-Stepped Finite-Element Modeling of Three-Phase Transformer for Electromagnetic Transient Emulation on FPGA

IEEE Open Access Journal of Power and Energy, 2021
The finite-element analysis is a powerful method to obtain detailed insight into the operation of any electromagnetic equipment. However, the required computational power to solve a finite-element modeled power equipment is so heavy that most Newton ...
Qingjie Xu, Peng Liu, Venkata Dinavahi
doaj   +1 more source

Aggregating distributed energy resources for grid flexibility services: A distributed game theoretic approach

International Journal of Robust and Nonlinear Control, EarlyView., 2023
Abstract We propose a hierarchical energy management scheme for aggregating Distributed Energy Resources (DERs) for grid flexibility services. To prevent a direct participation of numerous prosumers in the wholesale electricity market, aggregators, as self‐interest agents in our scheme, incentivize prosumers to provide flexibility. We firstly model the
Xiupeng Chen, Mehran Shakarami, Jacquelien M. A. Scherpen, Nima Monshizadeh   +3 more
wiley   +1 more source

Low-complexity signal detection algorithm based on preconditioned conjugate gradient method

Dianxin kexue, 2016
For large-scale multiple-input multiple-output system，minimum mean square error signal detection algorithm is near-optimal but involves matrix inversion，and complexity is growing exponentially.
Hua QU, Jing LIANG, Jihong ZHAO, Weihua WANG   +3 more
doaj   +2 more sources

Photothermal Macroporous Lignin Cryogels for Off‐Grid, Continuous Atmospheric Water Collection via Interlayer Heat Recovery

Advanced Functional Materials, EarlyView.
Photothermal, macroporous lignin‐based cryogels are engineered to convert sunlight into low‐grade heat. Integrated as stacked beds in a drum‐type device, a thin copper interlayer transfers waste heat between beds, enabling interlayer heat recovery and continuous solar cycling.
Jie Yan, Jiqing Lu, Tian Bai, Lin Li, Zhaoxuan Niu, Yiying Yue, Wanli Cheng, Guangping Han, Orlando J. Rojas   +8 more
wiley   +1 more source

Parallel RFSAI-BFGS Preconditioners for Large Symmetric Eigenproblems

Journal of Applied Mathematics, 2013
We propose a parallel preconditioner for the Newton method in the computation of the leftmost eigenpairs of large and sparse symmetric positive definite matrices.
L. Bergamaschi, A. Martínez
doaj   +1 more source